[PATCH] bpf: don't kfree an uninitialized im_node

From: Colin King
Date: Tue Jan 24 2017 - 09:17:46 EST

From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

There are some error exit paths to the label 'out' that end up
kfree'ing an uninitialized im_node. Fix this by inititializing
im_node to NULL to avoid kfree'ing a garbage address.

Issue found by CoverityScan, CID#1398022 ("Uninitialized pointer read")

Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
kernel/bpf/lpm_trie.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
index ba19241d..144e976 100644
--- a/kernel/bpf/lpm_trie.c
+++ b/kernel/bpf/lpm_trie.c
@@ -262,7 +262,7 @@ static int trie_update_elem(struct bpf_map *map,
void *_key, void *value, u64 flags)
struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
- struct lpm_trie_node *node, *im_node, *new_node = NULL;
+ struct lpm_trie_node *node, *im_node = NULL, *new_node = NULL;
struct lpm_trie_node __rcu **slot;
struct bpf_lpm_trie_key *key = _key;
unsigned long irq_flags;